3d paint effect in Blender
The best way would be to use a series of curves with a custom bevel. Create your paint patterns as a texture (with transparency enabled), and apply them to the curves.
It should take (except for the textures) just a few minutes.
Make your curve(s), adjust them using both handles and vertex weight and tilt, then in the curve tab apply bevel (half) (rounded) or whatever profile you want.
I did this with a very simple paint smear.

This is the node setup for the transparency

And this is the png I used. I had to adjust the z rotation to make the stripes the long way.
To get brush texture--not shown here--you can just run the image into a bump node for height and throw that into normal on the principaled BSDF shader.